2. What is RTM?
Resin Transfer Moulding is the process of
producing composite components within a
mechanically-clamped, rigid, normally two-part
(cope, drag) mould.
The principle behind composite manufacture is
the mixing of the reinforcement with
resin+catalyst mixture and the solidifying it using
heat and pressure into the net shape desired.
5. Recommended for:
High strength-to-weight requirements.
With very complex shape parts.
For mid-volume production in the range of 200 to
5,000 parts per year.
Gel coat can be employed for better finish on
both side surface.
Usually considered an intermediate process
between the relatively slow spray-up with lower
tooling costs and the faster compression molding
methods with higher tooling costs.
6. Materials Options:
Resins:
Generally epoxy, polyester, vinylester and
phenolic resins are used, although high
temperature resins such as bismaleimides can
be used at elevated process temperatures.
Fibres:
Any stitched/woven fabric materials work well
like glass fibre ,carbon fibre, aramid. Some
specially developed fabrics can assist with resin
flow.
7. Advantages:
High fiber volume laminates can be obtained with
very low void contents.
Volatile emissions like styrene are massively
reduced.
High repeatability can be achieved.
The laminate thickness can be closely controlled.
Less dependent on the skills of the operator
Automation possible.
Both sides of the component can have good
finish.
Allows one to obtain even very complex neat-
shape parts.
8. Disadvantages:
Matched tooling is expensive, and heavy in order to
withstand pressures.
Unimpregnated areas can occur resulting in very
expensive scrap parts.
Higher cycle times.
Large sized components needs very heavy and costly
moulds.
Can produce some thickness variation.
Low productive.
Not possible to determine whether the
reinforcement material is properly covered by the
resin
9. Applications:
In complex aircraft parts
Train seats
Truck panels
Boat hulls
Wind turbine blades
Aerospace and automobile parts
Medical composites
Bathroom fixtures, car body, helmet,
etc.
10. Modification (Vacuum RTM):
Also known as RTM Light.
Uses vacuum-clamped two part
(male/female) matched mould
Light weight mould design
Lower cost mould
Can provide good definition and extra
detail for upper moulded surface.
